The present invention relates to a fluid transmission device of a transmission to be mounted on a vehicle, particularly to a fluid transmission device which includes a dynamic vibration absorber, and falls under a technical field of a transmission for a vehicle.
Fluid transmission devices incorporated in a transmission, such as an automatic transmission or a continuously variable transmission mounted on a vehicle, for transmitting an output of an engine to a transmission mechanism, has a case coupled to an output shaft of the engine. The case accommodates a pump shell for rotating integrally with the case, and a turbine shell facing the pump shell. A drive force is transmitted between the turbine shell and the pump shell via fluid.
One type of such fluid transmission devices that is generally known includes a lockup clutch for directly coupling a pump shell side and a turbine shell side to each other, so as to improve a fuel economy of the engine.
Another type of such fluid transmission devices that is known includes a centrifugal pendulum-type damper as a dynamic vibration absorber for reducing vibration, so as to reduce torsional vibration of a drive system caused by a torque variation of the engine. For example, JP2012-077827A discloses a fluid transmission device including a centrifugal pendulum-type damper fixed to an output member for transmitting an engine output to a transmission mechanism side.
However, with the fluid transmission device described in JP2012-077827A, the centrifugal pendulum-type damper as the dynamic vibration absorber is enlarged in an axial direction thereof since it is disposed on an engine side of the pump and turbine shells of the device. Therefore, a size reduction in the axial direction is desired for a compact configuration.
Particularly with a fluid transmission device incorporated in a transversely-placed transmission having an axis extending in a width direction of the vehicle, if the axial dimension of the device is enlarged, the axial dimension of the entire transmission also becomes enlarged, which easily leads to interference with a frame member of a chassis, for example. Therefore, a size reduction in the axial direction is desired for a compact configuration.